Indicating device responsive to a condition



. AugQ-7, 1945. c. LEVY-SAVOYE 2,331,326

7 INDICATING' DEVICE RESPONSIVE TO A CONDITION Filed Sept. 18, 1942 3 Sheets-Sheet 1 xx I mm WNW;

1945' c. L EVY-SAVOYE 2,381,826

I INDIGATING DEVICE RESPONSIVE TO A CONDITION Filed Sept. 18, 1942 v s Sheets-Sheet 2 DASFLA CE'ME/VT I I mzsswrs can/15.5 'LEW-SA vo Aug. 7, 1945-- c. LEVY-SAVOYE 2,331,825

mmcawme DEVICE RESPONSIVE TO A CONDITION Filed Sept. 18, 1942 3 Sheets-Sheet 3 Patented Aug. 7, 1945 e UNITED STATE mmonrmo DEVICE imsroNsivE TO A connrrron Charles Levy-Savoye, New York, N. Y., assignor to General Aircraft Equipment, Inc., a. corporation of Connecticut Application September 18, 1942, Serial No. 458,912

2 Claims.

invention relates to a system for obtaining indications. I

One of the major problems in aviation today resides in providing the crew of an aircraft with means for checking the working conditions of the engine at any desired instance during its operation. In other words, it is necessary to provide the crew with correct data at all times concerning the oil pressure, oil temperature, water temperature, fuel pressure, number of revolutions, intake air pressure, intake air tem perature and other factors of which the crew must be constantly aware. Heretofore this data has been obtained by various means, such as for instance, the oil pressure has been measured through the use of a tube passing from the engine to the cockpit and linked to a corresponding pressure gauge. Temperatures, for example, are transmitted in a similar manner bymeasuring the pressures of a given vapor.

The present invention as applied to an aircraft *e'ngine or the like permits various factors such as those indicated above to be taken at the en- .,gine while direct readings of the variations are available in the cockpit. The principal object of the invention is to provide a device which will accomplish this result. v v

The major object of the present invention resides in providing a device as merely electrical in nature for the purpose ofcheckin'g, at a distance, the values of variable temperatures and pressures no matter what the external atmos- Figure 7 illustrates one-modiiication of the invention adapted to indicate changes in pressure.

Figure 8 shows-a furthermodiflcation of'the invention adapted to indicate variations intern perature.

Figure 9 shows a modification of the cylindrical member shown in Figure 1.

Figure 10 shows a relay. system adapted to be controlled from the cockpit and'is adapted to .maintain a, current of higher value through the electrical circuit.

Referring now more specifically to Figure 1 of the drawings, the reference numeral 2 indicates an electrical motor which is energized through any suitable source of electromotive force 4, the motor 2 having an externally extending rotating shaft 6 on which a, cylindrical member'il is fixed to rotate therewith. Thecylindrical member 8 is formed of two sections In and I2, respectively, section III consisting of a good electrical conductor, whereas, section I2ris comprised of an insulating material.

A serieselectrical circuit is employed comprising a conduit l4, one end of which is maintained in sliding continuous contact. with the conducting section of cylinder 8 and the other end of which terminates on one of the binding posts (not shown) of the thermo-ammeter iii. The other terminal of the thermal ammeter is connected directly to an electromotive source comprising preferably a, battery i8, the other terminal of the battery l8 being connected to a conductive rod 20, adaptedto 'be pivoted about the point 22. The rod 20 is provided with a contacting element 24 which is adaptedto be held in engagement with t the exterior surface of the cylinder 8. A second vision of a system which is simple and reliable in operation and easy to manufacture thus being admirably adapted for war production,

Other and further objects of the invention will become more apparent from the following description and claims when read in connection Figure 2 is a cross section taken on the lines =-2-2 of Figure 1.

Figure 3 is a cross section taken on the line Y of Figure 1.

Figure 4 is a graphical representation indicatrod 25 is connected to the rod 20 intermediate the pivoting point 22 and the element 24, the rod 26 being adapted to be moved laterally.

Hence it will be seen that as the rod 26 is moved either to the right or left as viewed in Figure 1, the contacting element 24 will be shifted to such a degree' that it will, if for instance moved to the left, remain in contact with the conducting surface of r the cylinder for a length of time indicated gener- .ing the length of current flow in the electrical contacting element over the various section lines.

261s adapted to beconnected with a temperatutl. or pressure responsive device or some other mov-v able element representing an operating factor, and capable of producing a lateral displacement" of the rod 26. As the rod 26 is displaced to the left of Figure 1, contact head 24 moves to the left of the constantly rotating cylinder 8 and consequently remains in contact with the conducting portion of the cylinder 8 for an increasingly longer period of time than it does on the insulating portion of the cylinder 8. During'the course of the timethat the contact element 24 remains, in contact with the conductive material on the now be made to specific means showing the adaptation of the devicefor changes in temperatures and pressure. In Figure 7 there is illustrated a Sylphon tube 28 which may be filled with any desired liquid. A spring means II is also provided against which the expansion of the Sylphon tube acts. Rigidly secured to one end of the Sylphon tube is the rod 28, A variation in the change of the pressure of the confined liquid will produce a movement of the Sylphon tube which is in turn directly communicated to the rod 20 which forces the rod 2| to rotate about its pivot 22. It becomes obvious from this type of arrangement that the length of time current passes through the ammeter ll may be interpolated upon suitable scales to give a direct reading of any change :in presber 24 does not make good electrical contact therewith. Such a condition might well affect and render inaccurate the readings on the ammeter. To overcome this difliculty, a circuit sys tem as illustrated in Figure 10, may be employed. In this system, the line 40 is provided with a pivoted switch arm 42, adjacent to which is located the solenoid 44, so that, upon energizetion of the solenoid when the contact 24 rides on the conducting portion of cylinder 8, the switch arm 42 will be moved to closed position. Consequently, current of higher value flows into the ammeter and. its reading is not affected by the condition of the conducting surface of the cylinder 8 or the effectiveness of the electrical contact between such surface and the contact point 24.

- I claim:

1. An indicating device comprising a cylinder, means for rotating said cylinder at a constant rate of speed, said cylinder having its exterior surface provided with alternating strips of conductive and non-conductive material, each of said alternating strips being tapered in width, 8. pair of spaced electrical contacts adapted to bear against the exterior surface of said cylinder, at

Again,,in Figure 8, there is illustrated one emtrical circuit thereby affording means for determining the actual change in temperature. Here, as in the modification illustrated in Figure 7, the length of time which the current flows through Iuh:l circuit must be interpolated upon a proper In Figures 2 and 3, there is illustrated a cross section of th'e cylinder 8 taken along the lines 2-2 and 3-4, respectively. It will be seen that the insulating portion i 2 has been provided with aflat portion 34. This portion has been cut away in order to reduce the friction of the contact head 24 against the portion l2 to an absolute minimum. In providing a flattened surface, such as I4, upon a cylinder I, the contact head 24 will be retained in its position butin spaced relationship to the cylinder. This reduces wear not only on the contact head but also upon the external surface of the cylinder.

- In Figure 9 there is illustrated a further modification of this invention wherein a plurality of contact elements 24 are provided. Such a system permits one to take readings of temperatures and not only in onepart of the aircraft engine, but in many parts thereof. As illustrated in 9, this modification is suitably adapted i l yed upon a motor airplane time the current will flow th'rough the series elecleast one of said contacts being movable with respect to the longitudinal axis of said cylinder, an electric circuit the component parts of which are connected in series with said electrical contacts, said parts comprising an electrical battery and a solenoid, and a second electrical circuit adapted to be connected in-parallel with said series circuit when said solenoid is energized, said second circuit including a thermal ammeter connected in series therewith and means responsive to variations in pressure, said means being coupled to said movable contact to impart movement thereto.

2. An indicating device comprisin a member substantially cylindrical in configuration, said member adapted to be rotated at a constant speed, a motor for rotating said member, said member having alternate conductive and nonconductive exterior surface areas of varying widths, an electrical contact adapted to ride in a fixed position over the surface of said member, a second electrical contact adapted to bear on portions of said exterior surface of said member and being adjustable with respect to the ends of said member, an

electrical circuit the component parts of which are connected in series with respect to said electrical contacts, said circuit comprising a thermal ammeter and a source of electro-motive force having a constant current value means for adjusting the second contact on th surface of said member in such a manner as to permit said second contact to remain in contactwith said conductive surface for a greater or lesser length of time, said cylindrical member having a portion cut away to provide a flattened surface on said non-conductive exterior surface of said member whereby-said electrical contacts are-retained out of engagement with said non-conductive material during a portion ofthe revolution of said cylindrical member,, J

navy-"savers; 

